The manufacture of bags such as the open mesh bags commonly used for the transportation and marketing of vegetables has progressed from the manual or stack cutting of bag material followed by manual sewing on a machine by an operator. Semi-automated machines have come into use with one or more of the operations conducted without operator attendance. Fully automated bag making machines have been a long felt need, however, none seem to have met all of the requirements of the industry or have such low throughput as to be uneconomic.
We have carefully examined the needs of bag producers and semi and automated machines available and have recognized the continuing need. Below are patents which are representative of the state of the art of bag making, known to the applicants:
U.S. Pat. No. 3,227,119 G. T. Gore, et al Jan. 4, 1966
This patent shows an exemplary apparatus for producing pillowcases, bags and the like in which continuous material is cut into individual sections before folding. The bags are sewn by moving sewing machines.
U.S. Pat. No. 3,424,113 E. D. Dickmann Jan. 28, 1969
His patent shows apparatus for sewing the end of tubular bag material with a tape and subsequently cut into individual bags at the tape.
U.S. Pat. No. 3,459,142 H. B. Berg Aug. 5, 1969
A bag stitching machine is disclosed in which the material is transported flat to a first fixed sewing machine, one seam sewn the bag is turned 90 degrees and then the next seam is sewn.
U.S. Pat. No. 4,224,883 Zeigler, Jr. et al Sep. 30, 1980
U.S. Pat. No. 4,214,541 Zeigler, Jr. et al Jul. 29, 1980
These two related patents show method and apparatus for manufacturing pillowcases in which continuous material is first hemmed, then cut into individual blanks and then folded for further processing.
U.S. Pat. No. 4,388,679 Everett, Jr. et al Jun. 21, 1983
Apparatus is disclosed for manufacturing pillowcases from continuous tubular material.
U.S. Pat. No. 4,580,509 Schell, et al Apr. 8, 1986
A system for sewing thread connected individual workpieces which are only connected together by the thread connection.
U.S. Pat. No. 4,685,407 H. Junemann Aug. 11, 1987
This patent discloses apparatus for flat sewing various garment parts such as sleeves and pocket shaped workpieces such as cuffs.
U.S. Pat. No. 4,754,717 Henze, et al Jul. 5, 1988
Disclosed is apparatus for forming covers by first cutting each section and then transporting each section flat for folding and subsequent sewing by fixed sewing machines.
U.S. Pat. No. 4,821,656 Dordi, et al Apr. 18, 1989
This patent represents apparatus for forming a cover for a mattress directly on the carcass or body of the mattress by forming beaded seams at each corner.
These patents reflect the need for automated or semi-automated apparatus for the production of bags or bag like sewn assemblies but fail to disclose the features set forth below which we have been able to develop and incorporate into our invention:
1. The use of a rotating drum which provides the functions of folding each bag blank, holding a series of folded blanks, cutting the folded blanks into individual blanks and delivering them to a position for transport, sewing and stacking. PA0 2. Individual clamp members on the periphery of a drum which tension a width of the bag material for cutting with a transverse moving cutter. PA0 3. The use of a reciprocating folding blade which aids in holding material in a bag fold making clamp until the jaws are fully closed to maintain tension on the bag material and the required fold size until the material is cut. PA0 4. The feature in which the reciprocating overlapping carriers each have a holddown member to hold the material adjacent to the sewing machine head but one of the holddown members is automatically retracted when in a non-material holding condition for non-interfering passage of the two reciprocating carriers. PA0 5. The presence of reciprocating, overlapping carriers for each bag through a fixed sewing machine for sewing at least one seam. PA0 6. The process including the step of folding a continuous strip of bag material before cutting into individual bag blanks allowing the tensioning of the uncut strip to aid in the folding, transferring and cutting operations.